Seems like it carefully worded marketing ********* . There are no free calls:
"With the XFINITY Voice Unlimited plan, you can make calls to nearly half the world, at home or on the go with your smartphone or tablet."
This just states that the xfinity connect app works for calls to these countries.
"Save on your wireless plan when you call Canada, China, India, Mexico, South Korea, Hong Kong, Singapore and Puerto Rico – at no additional cost."
And calls on your wireless device are no more expensive than calls from home phone, "No additional cost", but compared to what is not specified.
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